Zoonotic agents are those that can be transmitted between species; zoonoses that can be transmitted between humans and animals fall under the auspices of Animal Biosafety. Human exposure can occur through multiple routes, including bites, scratches, aerosol droplets, mucosal secretions, feces or urine. For animals inoculated with agents that are infectious but not necessarily to humans, there is the concern of transmission among a susceptible animal colony, and these agents fall under the auspices of Animal Biosecurity. While many laboratory animal species are bred to be free of zoonoses, there are zoonotic agents associated with laboratory animals, some of which can pose a risk to humans or other animals in the colonies (See Appendix D). Additionally, humanized animals (those administered or implanted with human tissues or cells) capable of supporting replication of human agents, animals with altered genotypes resulting in new or increased susceptibility to infectious agents, and animals with altered immune systems (such as severe combined immunodeficient, or SCID, mice) require specific risk assessments for zoonotic issues.
Table 2. Animal-specific work practices that are incorporated into research in addition to the basic BSL work practices outlined in Chapter 3.
| Work Practices | ABSL1+ | ABSL2 | ABSL3 |
|---|---|---|---|
| Access | Limited | Limited | Limited |
| Animal housing and equipment | Handled in a manner that minimizes contamination of other areas; Cage changes occur in a BSC; Method for decontamination is available |
Handled in a manner that minimizes contamination of other areas; Cage changes occur in a BSC; Method for decontamination is available inside the facility |
|
| Animal Support Staf | Receive training and annual updates; can perform cage changes for animals after the lab performs the first cage change | Receive training and annual updates; can perform cage changes for animals after the lab performs the first cage change for agents approved by Biosafety and the VSC | Receive training and annual updates; perform only welfare checks on animals unless otherwise approved by Biosafety and the VSC |
| BSC | Recommended for procedures with potential to create aerosols | Required for most procedures, particularly those with potential to create aerosols or for any utilizing aerosol transmissible pathogens | BSC or other containment devices required for all work where practical |
| Housing | Standard caging | Filter-top cages or actively ventilated-cages | Cages or housing system must incorporate aerosol protection |
| Medical Surveillance Program | LAOHP enrollment recommended/required based on animal species | LAOHP enrollment recommended/required based on animal species and agent used | LAOHP enrollment required based on animal species and agent used |
| PPE | Lab coat, gloves or other PPE as required by laboratory completion of the PPE Assessment Tool; Long pants and closed-toe shoes required | VSC-required PPE includes: disposable lab coat, disposable shoe covers, disposable head cover, gloves, surgical mask; Additional PPE required at direction of VSC or Biosafety |
Full-body disposable PPE (no exposure of street clothes); Respirator protection as determined by risk assessment |
| Sharps | Use of needles or syringes or other sharp instruments in the animal facility is limited to situations where there is no alternative for such procedures |
Use of needles or syringes or other sharp instruments in the animal facility is limited to situations where there is no alternative for such procedures; Animals should be manually or chemically restrained (anesthetized) during inoculation procedure, particularly those utilizing sharps |
Use of needles or syringes or other sharp instruments in the animal facility is limited to situations where there is no alternative for such procedures; Animal restraint (manual or chemical) required during inoculations |
| Signage | Cages labeled with VSC- designated tag indicating responsible person, agent, inoculation date and first cage change; Labels are updated to reflect when animals are no longer considered biohazardous but have been exposed to rDNA | Cages labeled with VSC- designated tag indicating responsible person, agent, inoculation date and first cage change; Lab must provide agent information to VSC so that door signs are updated appropriately |
Cages labeled with VSC- designated tag indicating responsible person, agent, inoculation date and first cage change; Lab must provide agent information to VSC so that door signs are updated appropriately |
| Waste | Transported in appropriate containers | Transported in appropriate containers; Excess inoculum is returned to laboratory for proper disposal; Decontamination by appropriate method is necessary for movement outside the designated housing area |
Transported in appropriate containers; Excess inoculum is returned to laboratory for proper disposal; Decontamination by appropriate method is necessary for movement outside the designated housing area |
Wild animals pose additional zoonotic risks, as their health history is unknown. Infectious agents or animals that pose a zoonotic threat are classified at the appropriate ABSL or Animal Biosecurity Level and are housed as such.
Most animals housed at ABSL1 are routinely tested for zoonotic agents of concern prior to arriving at Stanford and during any required quarantine period by the VSC. Sentinel animals in regular animal housing rooms are also routinely tested by the VSC, and if any zoonotic agents are identified, the VSC alerts EH&S to any potential associated risks. These tests are done to detect specific agents, and may not identify all possible zoonotic risks. It is therefore important that appropriate work practices and PPE as required by the VSC and Biosafety are followed. Sentinels and routine testing are not done in ABSL2 facilities, in PI-managed spaces, or with wild animals.
